This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Azure Dragon of the East gathers the first seven of the twenty eight lunar mansions, the lodges through which the moon and planets were tracked against the fixed stars in Chinese astronomy, read together as the horns, body and tail of the eastern quarter's guardian dragon.
Jiao, the Horn, opens the sequence at Spica in Virgo, heralding spring and read as auspicious for beginnings, construction and marriage. Xin, the Heart, centers on Antares, anciently the Fire Star lodge, carrying themes of passion and warning; Antares also anchors a mansion in the Indian nakshatra and Arabic lunar mansion systems, and shared anchors like this are among the reasons a common origin between the three schemes has been proposed, though the question remains unresolved and no direction of borrowing is established. Ji, the Winnowing Basket, closes the palace in Sagittarius, linked to wind and gossip.
The seven mansions are unequal in width by design rather than error: each is fixed by its own reference star and runs east to the next star, so a crowded stretch of sky produces a narrow lodge and a faint stretch a wide one, unlike the even divisions of a zodiac circle. Under the historical system of field allocation, each lodge was matched to a terrestrial region, so an omen observed in one of these seven was read as bearing on a specific province, making the eastern palace an instrument of statecraft as much as of astronomy.